Effect of heat treatment time on local structure of lanthanum-aluminum-gallium-borate xerogels

The aim of this study was to investigate the effect of 850 °C heat treatment time on LaAlGaB5O24 amorphous xerogel. Structural changes were evidenced by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. If xerogel remains non-crystalline after 5 min treatment, nanocrystallites of LaAl2.03(B4O10)O0.54 type are developed after 15 min treatment and this is the sole crystalline phase preserved by increasing the treatment time up to 24 h. Boron, aluminum and gallium units from amorphous xerogel are drastically changed by crystallization, but they are only slightly affected by increasing the 850 °C treatment from 15 min to 24 h.